Purpose: Bilateral fatigue femoral fractures (BFFF) represent an extremely rare clinical entity. The present study introduces a novel classification, in order to categorize the BFFFs and provide a thorough review of all these, so far in the literature, reported cases. Methods: The BFFF were classified taking into account the anatomical region of the femoral fracture; (fh): femoral head, (sc): sub-capital, (pt): peri-trochanteric, (st): sub-trochanteric, (s): shaft, (d): distal femur and the fracture type (complete or incomplete); type I: bilateral incomplete fractures, type II: unilateral incomplete fracture, and type III: bilateral complete fractures. Type III was further subdivided into type IIIA: bilateral non-displaced fractures, type IIIB: unilateral displaced fracture, and type IIIC: bilateral displaced fractures. Furthermore, a meticulous review of the PubMed and MEDLINE databases was conducted to locate all articles reporting these injuries. Results: A total of 38 patients (86.8% males), with a mean age of 25.3 years, suffering BFFFs were identified from the literature search. The mean time interval from symptoms' onset to diagnosis was 54 days. According to the proposed classification, 2.6% of the fractures were categorized as type I (h), 36.8% as type I (sc), 2.6% as type I(st/s), 7.9% as type I (s), 2.6% as type I (d), 5.4% as type II (fh), 26.3% as type II (sc), 2.6% as type IIIA (st), 2.6% as type IIIA (d), 5.4% as type IIIB (sc), 2.6% as type IIIB (d) and 2.6% as type IIIC (sc). Surgery was performed in 52.6%, while non-operative treatment was followed in 47.4% of the population. Regarding the fracture type, 75% of type I fractures were conservatively treated, while 91.7% and 66.6% of type II and III fractures were surgically treated. For patients treated conservatively, the mean time from diagnosis to return to previous status was 260 days, while for patients treated surgically, 343 days. Conclusions: BFFFs, although rare, may pose a diagnostic and therapeutic challenge. The present classification offers valuable information and may act as a guide for the management of these patients.
Keywords: classification; fatigue injury; femur fracture; fracture anatomical site; stress fracture.